Shell task control

jobs

• command1 & runs command1 in the background.
• jobs lists the current jobs in the environment.
• CTRL-Z sleeps a command with SIGSTOP.
• bg [job_id] sends a job to the background.
• fg [job_id] gives a job foreground control (input stream)

Killing programs

CTRL-C usually cancels the foreground command by sending SIGINT (C) or a KeyboardInterrupt (Python).

If you have zombie processes or frozen applications, simply find them and shut them down through the task manager (gnome-system-monitor). Or,

• ps displays information about the current process (probably the shell) and its child processes (background processes executed by the shell).
  • ps -g displays information about all running groups of commands.
• pidof PROGRAM reports the pid of that program.
• kill -kill PID or kill -9 PID sends SIGKILL (which cannot be caught or ignored), terminating the process.
• killall PROGRAM ends processes by name.
• top or htop are high-level text-mode task managers.